PATHOPHYS: URTIs Flashcards
What is otitis media?
Infection of the middle ear caused by viruses or bacteria.
What are the important causative pathogens of otitismedia?
Strep pneumoniae H. Flu Moraxella catarrhalis RSV Coronavirus Rhinovirus
What is the most common predisposing factor to otitis media?
seasonal allergic rhinitis
Who gets otitis media?
children under 3
Why are young children most likely to develop otitis media?
they have small opening of the eustachian tube that is easily blocked by inflammation caused by viral infection/allergic response (which will cause fluid retention and infection in the middle ear)
What are the physical findings of otitis media?
erythematous tympanic membrane with loss of light reflex and decreased mobility (sometimes tympanic membrane may bulge and rupture)
HOw do you treat otitis media?
amoxicillin
What is sinusitis?
inflammation of the paranasal sinuses
What causes sinusitis?
impaired mucociliary clearance caused by viral infection or allergic rhinitis can obstruct the orifice of the sinus leading to mucus accumulation and bacterial overgrowth
Which sinuses does sinusitis typically involve?
maxillary sinus (ostium of sinus is superior so mucus drainage has to go against gravity)
What are symptoms of sinusitis?
Purulent nasal discharge
Nasal congestion
Facial/sinus pain
Fever
What are the important pathogens of sinusitis?
S. pneumoniae
H. flu
M. Catarrhalis
What is the treatment for sinusitis?
if symptoms last over ten-fourteen days, give amoxicillin (or augmentin if resistant)
What is pharyngitis?
inflammation of the throat caused primarily by viruses (ex. adenovirus)
What bacteria are involved in pharyngitis?
Strep pyogenes (GAS) Neisseria gonorrhoeae (sexually) Corynebacterium diptheriae (where no diptheria vaccine is given) Mycoplasma, chlamydia, etc.
What are the symptoms/signs of pharyngitis?
sore throat that is worse when swallowing Fever Inflamed pharynx, tonsils, and palate Greyish exudate on tonsils Lymphadenopathy (tender) Petetchiae on palate
How do you diagnose a GAS pharyngitis?
rapid antigen detection tests
How do you treat GAS pharyngitis?
penicillin G, penicillin V, or amoxicillin
Erythromycin or cephalexin if penicillin allergy
True or false: most sore throats are bacterial.
FALSE: most are viral, so prescribing antibiotics is a major problem!
What is the common cold?
viral infection of the URI
What types of viruses cause the common cold?
nonenveloped viruses like rhinovirus and coronavirus
What may help to reduce symptoms of the common cold?
Zinc acetate in doses greater than 75 mg/day
What is croup?
inflammation of the larynx, trachea, and large bronchi
What is the key finding of croup?
inspiratory stridor
Barking cough
What is the most common cause of croup?
parainfluenza virus
RSV
Flu
What radiologic manifestation may indicate croup?
“steeple sign” which is subglottic tracheal narrowing
What is the treatment of the croup?
corticosteroids (ex. dexmethasone)
with or without epinephrine
What is laryngitis?
inflammation of the vocal cords of the larynx
What are the common clinical manifestations of laryngitis?
hoarseness
aphonia
What is the most common cause of laryngitis (top 2)?
parainfluenza virus
rhinovirus
How do you treat laryngitis?
hydration
voice rest
What is epiglottitis?
inflammation of the epiglottis
What are the clinical manifestations of epiglottitis?
rapidly worsening sore throat odynophagia (pain swallowing) dysphagia (difficulty swallowing) muffled voice MEDICAL EMERGENCY for young children because may cause airway obstruction
What is the most common cause of epiglottitis?
H. influenzae type B
What is seen on indirect laryngoscopy of a patient with epiglottitis?
swollen, cherry red epiglottis
What radiologic finding may be indicative of epiglottitis?
“thumb” sign (enlarged epiglottis)
What is the treatment for epiglottitis?
IV ceftriaxone
maybe corticosteroids to reduce inflammation
Is someone with a cold caused by rhinovirus at risk for pneumonia?
no Rhinovirus does NOT cause LRTI
Is someone with a cold caused by coronavirus at risk for pneumonia?
NO coronavirus does not cause LRTI (unless it is SARS or MERS)
Can rhinovirus survive in the GI tract?
NO–they are acid labile (killed by gastric acid when swallowed)
Can coronavirus survive int he GI tract?
yes!
Why do we not have a vaccine for rhinovirus?
because there are too many serotypes (over 100)
How many serotypes are there for strep pneumo?
93
What is the major pathogenesis of rhinovirus?
Chemical mediators of inflammation cause congestion and mucous secretion (LOOK BACK)
What is a common complication of URTI?
acute bacterial sinusitis
What is second line treatment for otitis media?
Augmentin
How long do children get observed?
48-72 hours
What is the pathogenesis of diptheria?
A-B toxin blocks protein synthesis by inactivating EF-2 by ADP ribosylation,resulting in decreased protein synthesis
What is the pathogenesis for H. flu?
Produces IgA protease facilitating attachment to the mucosa, also is encapsulated and evades phagocytosis.
What is the receptor for rhinovirus?
ICAM-1
What is the most typical epidemiology for epiglottitis patient?
Urbanmale in his 40s with rapid onset of sore throat, muffled voice, and odynophagia/dysphagia
Why are ear infections more common in children?
Ear infections are more common in children because their Eustachian tubes are shorter, narrower, and more horizontal than in adults.